package com.credit.core.util;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;

public class HashUtil {

public static  Long hash(String key) {  
        
        ByteBuffer buf = ByteBuffer.wrap(key.getBytes());  
        int seed = 0x1234ABCD;  
          
        ByteOrder byteOrder = buf.order();  
        buf.order(ByteOrder.LITTLE_ENDIAN);  
  
        long m = 0xc6a4a7935bd1e995L;  
        int r = 47;  
  
        long h = seed ^ (buf.remaining() * m);  
  
        long k;  
        while (buf.remaining() >= 8) {  
            k = buf.getLong();  
  
            k *= m;  
            k ^= k >>> r;  
            k *= m;  
  
            h ^= k;  
            h *= m;  
        }  
  
        if (buf.remaining() > 0) {  
            ByteBuffer finish = ByteBuffer.allocate(8).order(  
                    ByteOrder.LITTLE_ENDIAN);  
            // for big-endian version, do this first:   
            // finish.position(8-buf.remaining());   
            finish.put(buf).rewind();  
            h ^= finish.getLong();  
            h *= m;  
        }  
  
        h ^= h >>> r;  
        h *= m;  
        h ^= h >>> r;  
  
        buf.order(byteOrder);  
        return h;  
    }  
    
}
